1. Field of the Invention
The present invention relates to a multi-beam semiconductor laser device including a plurality of light emitting sections, and particularly relates to a semiconductor laser device having a junction up mount configuration.
2. Description of the Related Art
From the past, the semiconductor laser device of this type has been used in an electric device such as a laser beam printer. In the semiconductor laser device, on a plurality of strip-shaped ridges in which light emitting sections (emitters) are formed, strip-shaped electrodes (upper electrodes) are provided, respectively. Pad electrodes for external extraction are electrically connected to the strip-shaped electrodes, respectively. Further, an isolating groove is provided between the emitters adjacent to each other, and each emitter is independently driven (for example, Japanese Unexamined Patent Publication No. 2000-269601). In such a multi-beam laser device, with size reduction of the device in recent years, a beam pitch is a narrow pitch of approximately several tens of μm.
FIG. 11 illustrates the planar structure of such a multi-beam laser device of the narrow pitch type. This multi-beam laser device is manufactured in the following procedures. That is, after a plurality of strip-shaped ridges 101 including emitters are formed on a substrate 100, upper electrodes 102 are formed on the ridges 101 through the use of evaporation method, respectively. Next, after electrically isolating between the emitters by forming isolating grooves 103 between these ridges 101, respectively, the whole surface is once covered with an insulating film 104. After that, contact windows 105 corresponding to the upper electrodes 102, respectively, are formed in the insulating film 104. As illustrated in FIG. 11, there is a case where this contact window 105 is formed only immediately below a wiring layer 106, or there is a case where the contact window 105 is formed to have a heat release region larger than the region immediately below the wiring layer 106. For the purpose of electrically connecting the upper electrode 102, and the wiring layer 106 and the pad electrode 107, the plurality of contact windows 105 are manufactured in uniform size with respect to each emitter.